Configuration for Compact Five Speed Planetary Transmission

ABSTRACT

A compact five-speed transmission planetary gear train includes a first, second, third, fourth and fifth planetary gear sets between an input and an output as well as first, second, third and fourth brakes and first and second clutches. The first, second, third and fourth brakes and first and second clutches are selectively actuatable to provide five different forward speeds and a plurality of different reverse speeds between the input and the output.

TECHNICAL FIELD OF THE DISCLOSURE

The present disclosure relates to mechanical power transmission and,more particularly, relates to a compact and efficient5-forward/4-reverse transmission.

BACKGROUND OF THE DISCLOSURE

Because most power sources have a limited range of output RPM, machinesemploying such power sources will also typically employ a multispeedtransmission to provide a greater range of machine speed. One type ofmultispeed transmission is the planetary transmission. Such atransmission generally includes many planetary gear sets linked togetherin various ways, with selectable elements used to select theinput/output ratio.

However, planetary gear sets take up a significant amount of space, andit is typically required to either settle for a limited number of gearranges or allow for a greater installation footprint to include agreater number of planetary gear sets. For example, U.S. Pat. No.8,105,198 to Hart et al. compromises in the former manner. The Hartpatent describes a compact transmission that includes four planetarygear sets and various clutches and brakes. The clutches and brakes areselectively engageable to provide different speed ratios, but only asingle reverse speed ratio is enabled. In other words, while a widevariety of forward speeds is provided, the operator has no choiceregarding reverse speeds since only a single reverse ratio is providedby the system.

The present disclosure is directed to a system that addresses one ormore of the problems set forth above. However, it should be appreciatedthat the solution of any particular problem is not a limitation on thescope of this disclosure nor of the attached claims except to the extentexpressly noted. Additionally, the inclusion of any problem or solutionin this Background section is not an indication that the problem orsolution represents known prior art except as otherwise expressly noted.

SUMMARY OF THE DISCLOSURE

In accordance with one aspect of the present disclosure, a machine powertransmission is provided comprising a planetary gear train having onlyfive planetary gear sets including a first planetary gear set having afirst sun gear, first ring gear, and first carrier, a second planetarygear set having a second sun gear, second ring gear, and second carrier,a third planetary gear set having a third sun gear, third ring gear, andthird carrier, a fourth planetary gear set having a fourth sun gear,fourth ring gear, and fourth carrier, and a fifth planetary gear sethaving a fifth sun gear, fifth ring gear, and fifth carrier. Thetransmission includes an input to the planetary gear train and an outputfrom the planetary gear train. Also included are a first brake, secondbrake, third brake, fourth brake, first clutch and second clutchassociated with the planetary gear train, the first brake, second brake,third brake, fourth brake, first clutch and second clutch being linkedto the planetary gear train such that selective actuation of one or moreof the first brake, second brake, third brake, fourth brake, firstclutch and second clutch provides five forward speeds and four or morereverse speeds. The first brake is positioned to brake the firstcarrier, the second brake is positioned to brake the second ring gear,the third brake is positioned to brake the fifth ring gear, the fourthbrake is positioned to brake the fifth sun gear, the first clutch ispositioned to tie the fourth sun gear to the fifth sun gear, and thesecond clutch is positioned to tie the fifth sun gear to the output fromthe planetary gear train.

In accordance with yet another aspect of the present disclosure, aplanetary gear train is provided having first, second, third, fourth andfifth planetary gear sets between an input and an output. The first,second, third and fourth brakes and first and second clutches, thefirst, second, third and fourth brakes and first and second clutches areselectively actuatable to provide five different forward speeds and fourdifferent reverse speeds between the input and the output. The firstbrake is positioned to brake a first carrier of the first planetary gearset, the second brake is positioned to brake a second ring gear of thesecond planetary gear set, the third brake is positioned to brake afifth ring gear of the fifth planetary gear set, the fourth brake ispositioned to brake a fifth sun gear of the fifth planetary gear set,the first clutch is positioned to tie a fourth sun gear of the fourthplanetary gear set to the fifth sun gear, and the second clutch ispositioned to tie the fifth sun gear to the output from the planetarygear train.

In yet another aspect of the present disclosure, a compact transmissionis provided having five forward speeds and four reverse speeds, thecompact transmission including five or fewer planetary gear sets, fouror fewer brakes for braking one or more elements of the planetary gearsets, and two or fewer clutches. Two of the brakes are activated on amutually exclusive basis to select a transmission direction and allothers of the brakes and clutches are activated in a least one forwardspeed and at least one reverse speed.

Other features and advantages of the disclosed systems and principleswill become apparent from reading the following detailed disclosure inconjunction with the included drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a transmission system and associatedsystems in keeping with an embodiment of the described principles;

FIG. 2 is a planetary gear set diagram showing a transmission system inaccordance with an embodiment of the described principles;

FIG. 3 is a gear ratio chart showing ratios as well as clutch and brakeactivation patterns for each gear in accordance with the transmission ofFIG. 2;

FIG. 4 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 1 F configuration;

FIG. 5 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 2F configuration;

FIG. 6 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 3F configuration;

FIG. 7 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 4F configuration;

FIG. 8 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 5F configuration;

FIG. 9 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 1R configuration;

FIG. 10 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 2R configuration;

FIG. 11 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 3R configuration; and

FIG. 12 is a power flow diagram showing the power flow in thetransmission of FIG. 2 in a 4R configuration.

DETAILED DESCRIPTION OF THE DISCLOSURE

The present disclosure provides a configuration for a compact five-speedplanetary transmission. The transmission in an embodiment includes fiveplanetary gear sets configured via four static clutches (also referredto herein as brakes) and two rotating clutches. In an embodiment, theseelements are located such that selective activation provides fiveforward speeds as well as four or more reverse speeds. In a furtherembodiment, the gear system is divided and includes distinct directionaland speed portions.

Having discussed various embodiments in overview, we turn now todetailed descriptions of certain embodiments. FIG. 1 is a systemschematic showing input, output, and control structures of a machinepower system 1 in accordance with an embodiment. In the illustratedconfiguration, the machine power system 1 includes a power input device2, which may be an engine such as a fuel-burning engine (gas, diesel,propane, LNG, kerosene, etc.) or a motor, e.g., an electric or hydraulicmotor.

The power input device 2 is linked into a planetary gear set 3 via aninput shaft 4. The state of the planetary gear set 3 (e.g., the outputspeed and direction of the planetary gear set 3) is controlled by afirst brake 5, second brake 6, third brake 7, and fourth brake 8, aswell as a first clutch 9 and second clutch 10. The planetary gear set 3,first brake 5, second brake 6, third brake 7, fourth brake 8, firstclutch 9 and second clutch 10 may be referred to collectively as thetransmission 25.

Each brake and clutch is controlled by a control element such as anelectronic solenoid valve, such that the machine power system 1 includesa first solenoid 11, second solenoid 12, third solenoid 13, fourthsolenoid 14, fifth solenoid 15 and sixth solenoid 16 linked to the firstbrake 5, second brake 6, third brake 7, fourth brake 8, first clutch 9and second clutch 10 respectively.

A controller 17 is connected and configured to control each of the firstsolenoid 11, second solenoid 12, third solenoid 13, fourth solenoid 14,fifth solenoid 15 and sixth solenoid 16. In an embodiment, thecontroller 17 actuates the solenoids to set the state of the planetarygear set 3 in response to a plurality of inputs. In the illustratedembodiment, the plurality of inputs includes a speed input 18 from thepower input device 2, and the controller 17 may also provide anacceleration output 19 to the power input device. The plurality ofinputs further includes an acceleration input 20 and a direction input21, both from a user interface module 22.

The user interface module 22 may be an interface to personnel in amachine cab or may be an interface to another electronic system, e.g.,for remote control or autonomous operation. The controller 17 in anembodiment is a digital processor operating in accordance withcomputer-executable instructions and data read from one or morenon-transitory computer-readable media, e.g., a volatile or nonvolatilememory associated with controller 17. The volatile or nonvolatile memoryassociated with controller 17 may include a flash drive, optical drive,magnetic drive and/or other appropriate memory device.

The planetary gear set 3 provides power to a final drive 23 via anoutput shaft 24, with the speed range and direction of the rotation ofthe output shaft 24 being set by the controller 17 via setting of thefirst solenoid 11, second solenoid 12, third solenoid 13, fourthsolenoid 14, fifth solenoid 15 and sixth solenoid 16.

As will be seen from FIG. 2, the illustrated transmission 25 isimplemented in an embodiment as a compact planetary gear system havingfive individual interconnected planetary gear sets. In particular, thetransmission 25 as illustrated includes a first planetary gear set 26, asecond planetary gear set 27, a third planetary gear set 28, a fourthplanetary gear set 29, and a fifth planetary gear set 30. Each planetarygear set includes a sun gear, ring gear and carrier.

Thus, the first planetary gear set 26 comprises a first sun gear 31, afirst ring gear 32, and a first carrier 33; the second planetary gearset 27 includes a second sun gear 34, a second ring gear 35, and asecond carrier 36; the third planetary gear set 28 includes a third sungear 37, a third ring gear 38, and a third carrier 39; the fourthplanetary gear set 29 includes a fourth sun gear 40, a fourth ring gear41, and a fourth carrier 42; and the fifth planetary gear set 30includes a fifth sun gear 43, a fifth ring gear 44, and a fifth carrier45.

In an embodiment, the first ring gear 32 is tied to the second carrier36, which is in turn tied to the third carrier. Similarly, the first sungear 31 and second sun gear 34 are tied to the transmission input 4. Thethird sun gear 37 is tied to the transmission output 24 and to thefourth carrier 42. The third ring gear 38 is tied to the fourth ringgear 41, which is in turn tied to the fifth carrier 45.

As noted above, the transmission 25 in an embodiment also includes aplurality of brakes and clutches. In the illustrated configuration, afirst brake 46 is linked to the first carrier 33 of the first planetarygear set 26, a second brake 47 is linked to the second ring gear 35 ofthe second planetary gear set 27, a third brake 48 is linked to thefifth ring gear 44 of the fifth planetary gear set 30, and a fourthbrake 49 is linked to the fifth sun gear 43 of the fifth planetary gearset 30. Each brake 46, 47, 48, 49 is configured to selectively tie theassociated component to the transmission case or other static structureand thus limit the rotation of the associated component.

Moreover, in the illustrated configuration, a first clutch 50 is linkedto the fourth ring gear 41 of the fourth planetary gear set 29, and asecond clutch 51 is linked to the fifth sun gear 43 of the fifthplanetary gear set 30. The first clutch 50 is selectively actuatable tolink the fourth ring gear 41 of the fourth planetary gear set 29 to thefifth sun gear 43 of the fifth planetary gear set 30 and the fifthcarrier 45 of the fifth planetary gear set 30. The second clutch 51 isselectively actuatable to link the fifth sun gear 43 of the fifthplanetary gear set 30 to the third sun gear 37 of third planetary gearset 28, which is also linked to the output shaft 24.

In operation, selective actuation of one or more of the first brake 46,second brake 47, third brake 48, fourth brake 49, first clutch 50, andsecond clutch 51 serves to place the transmission 25 into a selectedstate, e.g., one of five forward speeds or one of four reverse speeds.The chart 55 of FIG. 3 shows the corresponding states for selectiveactuation in the illustrated embodiment.

As can be seen, the first brake 46 and the second brake 47 acteffectively as directional selectors and are actuated on a mutuallyexclusive basis to select either a forward or a reverse outputdirection. The third brake 48, fourth brake 49, first clutch 50, andsecond clutch 51 are actuated in various patterns to select a gear ratiowithin the selected directional constraint.

In the illustrated embodiment, the following associations of [Ratio,Gear, First Clutch, Second Clutch, Third Brake, Fourth Brake, FirstBrake, Second Brake] respectively are exhibited: [4.262, 1F, On, Off,Off, On, On, Off]; [3.214, 2F, On, On, Off, Off, On, Off]; [2.389, 3F,On, Off, On, Off, On, Off]; [1.779, 4F, Off, On, On, Off, On, Off];[1.005, 5F, Off, Off, On, On, On, Off]; [−2.412, 1R, On, On, Off, Off,Off, On]; [−1.793, 2R, On, Off, On, Off, Off, On]; [−1.335, 3R, Off, On,On, Off, Off, On]; and [−0.754, 4R, Off, Off, On, On, Off, On].

It will be appreciated that the power flow through the transmission 25depends upon the selected direction and ratio. Thus, for each selectablegear 1F, 2F, 3F, 4F, 5F, 1R, 2R, 3R, and 4R, the power flow through thetransmission 25 is shown in respective ones of the power flow diagramsincluded in FIGS. 4-12.

FIG. 4 thus shows the power flow through the transmission 25 when thetransmission is in the 1F state (first forward gear). The states of the[First Clutch, Second Clutch, Third Brake, Fourth Brake, First Brake,Second Brake] respectively are [On, Off, Off, On, On, Off] in thisconfiguration.

FIG. 5 shows the power flow through the transmission 25 when thetransmission is in the 2F state (second forward gear). The states of the[First Clutch, Second Clutch, Third Brake, Fourth Brake, First Brake,Second Brake] in this configuration are [On, On, Off, Off, On, Off]respectively.

Shown in FIG. 6 is the power flow through the transmission 25 when thetransmission is in the 3F state (third forward gear). The states of the[First Clutch, Second Clutch, Third Brake, Fourth Brake, First Brake,Second Brake] in this state are [On, Off, On, Off, On, Off]respectively.

The power flow diagram of FIG. 7 illustrates the power flow through thetransmission 25 when the transmission is in the 4F state (fourth forwardgear). The states of the [First Clutch, Second Clutch, Third Brake,Fourth Brake, First Brake, Second Brake] in this state are [Off, On, On,Off, On, Off] respectively.

For the final forward state, 5F, FIG. 8 shows the power flow through thetransmission 25. The states of the [First Clutch, Second Clutch, ThirdBrake, Fourth Brake, First Brake, Second Brake] in this state are [Off,Off, On, On, On, Off] respectively.

Having reviewed the power flow in each of the forward gears, the powerflow in each reverse gear will be shown. FIG. 9 illustrates the powerflow through the transmission 25 when the transmission is in the 1Rstate (first reverse gear). The states of the [First Clutch, SecondClutch, Third Brake, Fourth Brake, First Brake, Second Brake] in thisstate are [On, On, Off, Off, Off, On] respectively.

The power flow through the transmission 25 when the transmission is inthe 2R state (second reverse gear) is shown in FIG. 10. The states ofthe [First Clutch, Second Clutch, Third Brake, Fourth Brake, FirstBrake, Second Brake] in this configuration are [On, Off, On, Off, Off,On] respectively.

In the 3R state (third reverse gear), all five planetary gear sets areagain involved in the power flow as shown in FIG. 11. In this state, theconfigurations of the [First Clutch, Second Clutch, Third Brake, FourthBrake, First Brake, Second Brake] are [Off,On, On, Off, Off, On]respectively.

The power flow through the transmission 25 in the final reverse state 4R(fourth reverse gear) is shown in the power flow diagram of FIG. 12. Inthis state, the configurations of the [First Clutch, Second Clutch,Third Brake, Fourth Brake, First Brake, Second Brake] are [Off, Off, On,On, Off, On] respectively.

It will be appreciated that the precise input/output ratio in each statewill depend upon the e-value of each planetary gear set. In theembodiment reflected in the state chart of FIG. 3, the e-value for thefirst planetary gear set is 2.412, the e-value for the second planetarygear set is 2.214, the e-value for the third planetary gear set is2.199, the e-value for the fourth planetary gear set is 2.108, and thee-value for the fifth planetary gear set is 1.854. Those of skill in theart will understand that other planetary gear set e-values may be usedto change one or more of the gear ratios shown in FIG. 3. Moreover, itwill be appreciated that the described principles include any trivialvariants.

INDUSTRIAL APPLICABILITY

In general terms, the present disclosure sets forth a compact5-forward/4-reverse transmission applicable to any machine wherein acompact space requirement exists and the indicated number and directionof gears are needed. The described system operates by the selectiveactuation of four brakes and two rotational clutches. The system isdivided in the sense that two brakes on two adjacent planetary gear setsserve as directional selectors, and the two adjacent planetary gear setsare tied into the remaining planetary gear sets via a single link. Theresultant system provides compact installation and efficient operation.In addition, the close step of the resultant system allows direct driveshifts in the working range.

It will be appreciated that the present disclosure provides a new anduseful transmission for use in a variety of machines. While only certainembodiments have been set forth, alternatives and modifications will beapparent from the above description to those skilled in the art. Theseand other alternatives are considered equivalents and within the spiritand scope of this disclosure and the appended claims.

What is claimed is:
 1. A machine power transmission comprising: aplanetary gear train having only five planetary gear sets including afirst planetary gear set having a first sun gear, first ring gear, andfirst carrier, a second planetary gear set having a second sun gear,second ring gear, and second carrier, a third planetary gear set havinga third sun gear, third ring gear, and third carrier, a fourth planetarygear set having a fourth sun gear, fourth ring gear, and fourth carrier,and a fifth planetary gear set having a fifth sun gear, fifth ring gear,and fifth carrier; an input to the planetary gear train and an outputfrom the planetary gear train; and a first brake, second brake, thirdbrake, fourth brake, first clutch and second clutch associated with theplanetary gear train, the first brake, second brake, third brake, fourthbrake, first clutch and second clutch being linked to the planetary geartrain such that selective actuation of one or more of the first brake,second brake, third brake, fourth brake, first clutch and second clutchprovides five forward speeds and four or more reverse speeds, the firstbrake being positioned to brake the first carrier, the second brakebeing positioned to brake the second ring gear, the third brake beingpositioned to brake the fifth ring gear, the fourth brake beingpositioned to brake the fifth sun gear, the first clutch beingpositioned to tie the fourth sun gear to the fifth sun gear, and thesecond clutch being positioned to tie the fifth sun gear to the outputfrom the planetary gear train.
 2. The machine power transmission inaccordance with claim 1, wherein the transmission is divided into adirectional portion of the transmission and a speed portion of thetransmission.
 3. The machine power transmission in accordance with claim3, wherein the directional portion of the transmission includes thefirst and second planetary gear sets.
 4. The machine power transmissionin accordance with claim 1, wherein a first forward speed is provided byactuation of the first clutch, first brake, and fourth brake.
 5. Themachine power transmission in accordance with claim 1, wherein a secondforward speed is provided by actuation of the first clutch, secondclutch, and first brake.
 6. The machine power transmission in accordancewith claim 1, wherein a third forward speed is provided by actuation ofthe first clutch, first brake, and third brake.
 7. The machine powertransmission in accordance with claim I, wherein a fourth forward speedis provided by actuation of the second clutch, first brake, and thirdbrake.
 8. The machine power transmission in accordance with claim 1,wherein a fifth forward speed is provided by actuation of the firstbrake, third brake, and fourth brake.
 9. The machine power transmissionin accordance with claim 1, wherein a plurality of reverse speeds areprovided by actuation of the second brake in combination with one ormore of the first and second clutches and the third and fourth brakes.10. A planetary gear train comprising: first, second, third, fourth andfifth planetary gear sets between an input and an output; and first,second, third and fourth brakes and first and second clutches, thefirst, second, third and fourth brakes and first and second clutchesbeing selectively actuatable to provide five different forward speedsand four different reverse speeds between the input and the output, thefirst brake being positioned to brake a first carrier of the firstplanetary gear set, the second brake being positioned to brake a secondring gear of the second planetary gear set, the third brake beingpositioned to brake a fifth ring gear of the fifth planetary gear set,the fourth brake being positioned to brake a fifth sun gear of the fifthplanetary gear set, the first clutch being positioned to tie a fourthsun gear of the fourth planetary gear set to the fifth sun gear, and thesecond clutch being positioned to tie the fifth sun gear to the outputfrom the planetary gear train.
 11. The planetary gear train inaccordance with claim 10, wherein the first, second, third, fourth andfifth planetary gear sets are divided into a directional portion and aspeed portion.
 12. The planetary gear train in accordance with claim 11,wherein the directional portion includes the first and second planetarygear sets.
 13. The planetary gear train in accordance with claim 12,wherein the first brake and second brake are activated on a mutuallyexclusive basis to select a transmission direction.
 14. The planetarygear train in accordance with claim 13, wherein a plurality of reversespeeds are provided by activation of the second brake in combinationwith one or more of the first clutch, second clutch, third brake, andfourth brake.
 15. The planetary gear train in accordance with claim 13,wherein a plurality of forward speeds are provided by activation of thefirst brake in combination with one or more of the first clutch, secondclutch, third brake, and fourth brake.
 16. The planetary gear train inaccordance with claim 13, further including an electrically actuatablesolenoid associated with each of the first clutch, second clutch, firstbrake, second brake, third brake, and fourth brake for activationthereof.
 17. The planetary gear train in accordance with claim 16,further including an electronic controller linked to each electricallyactuatable solenoid.
 18. The planetary gear train in accordance withclaim 16, further including a user interface module linked to theelectronic controller for receiving user commands.
 19. The planetarygear train in accordance with claim 13, wherein the input is linked to apower input device.
 20. A compact transmission providing five forwardspeeds and four reverse speeds, the compact transmission including fiveor fewer planetary gear sets, four or fewer brakes for braking one ormore elements of the planetary gear sets, and two or fewer clutches,wherein two of the brakes are activated on a mutually exclusive basis toselect a transmission direction and wherein all others of the brakes andclutches are activated in at least one forward speed and at least onereverse speed.